I’ve received quite a few responses to yesterday’s Web Developer Quiz, including some feedback about the type of questions I asked and criticism about them being too much about SGML which I’d like to take the opportunity to address.

Firstly, out of all the responses received in the last 24 hours (although, they’re not yet published), not one person has answered all questions correctly. Indeed, there are questions in there that no-one has answered correctly yet, which I am very surprised about — I was expecting to, at least collectively, receive the correct answers for all questions.

Secondly, I’m going to go through each section and explain, without giving away the answers just yet, why I asked each question and why it’s important for authors to know the answers to them.

Validation

Looking at the sample document, it’s not hard to see that it makes use of unsupported SGML features that cannot be used in the real world. However, this does not mean that authors do not need to be aware of them.

In fact, the document demonstrates just how easy it is to make unintentional use of such features, which, while it may not be what the author intended, will either result in one of two possibilites. 1. Completely unexpected errors that don’t seem to make sense: a problem I see a lot of beginners struggle with. 2. As is the case with this document, the combination of 2 specific authoring errors results in no validation error being reported at all, for the mistakes.

At this point, I’d like to point out that there is just 1 error within the document (most people have picked it so far), but it has nothing to do with the unsupported SGML features, and everything to do with the declared DOCTYPE. This will, perhaps, become more apparent to you when I reveal the answers and explain the reasons for the errors, or lack thereof, in more detail next week.

Elements in the DOM

The first of these questions is very much related to an unsupported SGML feature, rather than real world, practical HTML, and I admit, I just threw it in as a challenge for the more advanced authors. It is, however, important to be aware of the syntax and that it is unsupported, and thus cannot be used, even inadvertently.

The second question is testing your knowledge of real world, supported mark up. You need to be aware that start-tags and end-tags can be omitted for some elements, yet the elements will still be present in the DOM. You also need to be aware of the HTML/SGML comment syntax and, although it wasn’t really tested with these questions, the syntactic differences between SGML and XML comments.

Semantics

These are, perhaps, the easiest and most practical questions in the quiz. So far, nearly everybody has answered these questions correctly, and I don’t feel I need to explain why they were included, it seems quite obvious to everyone.

Character References

Surprisingly, nobody has correctly any of these 3 questions. Yet it is important from both a practical point of view and a validation point of view, to understand the similarities and differences between HTML, XHTML and XML with respect to character references. It is also important to have an understanding of the Unicode character repertoire and code points, which is what everyone has failed on, so far.

Media Types

Again, this is important from a practical perspective. Authors need to understand, that they should not use XHTML with the wrong media type, and also understand the practical limitations with doing so. Conversely, although this was not tested with these questions, it is important to understand the current practical limitations with using the correct media type for XHTML.

I’ll be revealing the answers including all the responses to the quiz on Sunday evening (local time). Until then, tell others, who haven’t seen it yet, about the quiz, I’m interested in finding out how much an average web developer really knows about the technologies they use every day.